Thermal ageing of barrier pigment paint films

Abstract

Purpose

The purpose of this paper is to evaluate the behaviour of commercial organic coatings in two proposed short time accelerated ageing methods.

Design/methodology/approach

Two cycles of accelerated ageing at different temperatures have been set out: dry heating and heating in immersion (humid). The dry ageing was carried out by warming up the film continuously over a 24 h period at three temperatures: 65, 85 and 100°C, until completion after ten days; the humid ageing was carried out by submerging some film samples in hot brine and maintaining them submerged for 24 h at 45, 65 and 85°C.

Findings

DSC and FTIR techniques reported that the coating suffered an “over‐cured” process after being submitted to the dry cycle. The films submitted to wet ageing developed micro‐cracks. Both ageing cycles caused physical degradation and a little sign of chemical degradation as shown by SEM observations.

Practical implications

The ageing cycles could be applied to organic coatings, maybe varying the temperatures according to the Tg of the resins employed, as well as the ageing time according to the hardness and resistance of the coatings.

Originality/value

The ageing cycles were proposed after a long review of the literature and the conditions employed were short enough for rapid evaluation and long enough to promote the degradation of the films.

Citation

Angeles, M.E., Magaña, C.R., Vázquez, F.S. and Rodríguez, F.J. (2007), "Thermal ageing of barrier pigment paint films", Anti-Corrosion Methods and Materials, Vol. 54 No. 6, pp. 341-345. https://doi.org/10.1108/00035590710833493